The Essex Wildlife Trust (EWT) is one of 46 wildlife trusts which cover the United Kingdom. The EWT was founded in 1959, and it describes itself as Essex's leading conservation charity, which aims to protect wildlife for the future and the people of the county. As of January 2017, it has over 34,000 members and runs 87 nature reserves, 2 nature parks and 11 visitor centres.
Ingrebourne Marshes are a 74.8 hectare biological Site of Special Scientific Interest in Hornchurch in the London Borough of Havering. Ingrebourne Valley Local Nature Reserve includes a small part of the SSSI west of the River Ingrebourne. The site is managed by the Essex Wildlife Trust
Aldbury Nowers is a 19.7 hectares biological Site of Special Scientific Interest (SSSI) in the Chiltern Hills, north-east of Tring in Hertfordshire. The site was notified in 1990 under the Wildlife and Countryside Act 1981. It is managed by the Hertfordshire and Middlesex Wildlife Trust. The site, formerly known as "Duchie's Piece," comprises two areas of hillside, linked by The Ridgeway. The calcareous meadow element of the site hosts the flowers of chalk grassland and has butterfly habitats with thirty-four different species of butterfly recently recorded, including the Duke of Burgundy, hairstreaks and the Essex skipper. The site also includes a "beech hanger", a type of upland ancient woodland, and is considered one of the best examples of this feature in Hertfordshire.
Patmore Heath is a 7.6 hectare biological Site of Special Scientific Interest in East Hertfordshire, 2 kilometres north-east of Albury, Hertfordshire. The site was notified in 1985 under the Wildlife and Countryside Act 1981. Patmore Heath is home to a large amount of dry grass, as well as marshy-areas. Much turf throughout the SSSI is dominated by Deschampsia, as well as occurrences of Anthoxanthum odoratum.
Wormley-Hoddesdonpark Wood North is a 143.9 hectare woodland area in Hertfordshire which has been designated as a biological site of Special Scientific Interest. The site is listed as Grade 1 in A Nature Conservation Review, and is also designated a Special Area of Conservation. It is in Hoddesdon in the borough of Broxbourne, but part of the site is in East Hertfordshire.
Herts and Middlesex Wildlife Trust manages over 40 nature reserves covering nearly 810 hectares north of London, in Hertfordshire and the historic county of Middlesex, part of which is divided between the London boroughs of Barnet, Enfield, Harrow and Hillingdon. It has over 21,000 members, and is one of 46 Wildlife Trusts across the UK. It is a Registered Charity, with its Registered Office in St Albans, and had an income in the year to 31 March 2014 of over £1.5 million.
Rye Meads is a 58.5 hectare biological Site of Special Scientific Interest (SSSI) in Rye House, Hoddesdon, Hertfordshire. It is one of series of wetlands and reservoirs situated along the River Lea, to the north-east of London. It is part of the Lea Valley Ramsar site and a Special Protection Area.
Old Park Wood is a 16.7-hectare (41-acre) Site of Special Scientific Interest in Harefield in the London Borough of Hillingdon. The south-east part is an 8-hectare (20-acre) nature reserve owned and managed by the Hertfordshire and Middlesex Wildlife Trust.
Mid Colne Valley is a 132 hectare biological Site of Special Scientific Interest in Harefield in the London Borough of Hillingdon and Denham in South Buckinghamshire. Its main importance lies in its extensive diversity of birdlife in lakes in former gravel pits.
Frogmore Meadows is a 4.6-hectare (11-acre) biological Site of Special Scientific Interest in Hertfordshire and Buckinghamshire, north of the village of Chenies. It consists of two meadows in the Chilterns Area of Outstanding Natural Beauty, next to the River Chess, one of which is a Hertfordshire and Middlesex Wildlife Trust nature reserve. The planning authorities are Three Rivers District Council, Dacorum Borough Council and Chiltern District Council.
Amwell Quarry or Amwell Nature Reserve is a 37 hectare biological Site of Special Scientific Interest in Great Amwell in Hertfordshire. The planning authority is East Hertfordshire District Council. It is also part of the Lee Valley Ramsar Site and Special Protection Area, and is owned and managed by the Hertfordshire and Middlesex Wildlife Trust.
Hunsdon Mead is a 34 hectare biological Site of Special Scientific Interest (SSSI) west of Harlow and east of Roydon in Essex. The site is partly in Essex and partly in Hertfordshire, and it is jointly owned and managed by the Essex Wildlife Trust and the Herts and Middlesex Wildlife Trust. The SSSI also includes part of the neighbouring Roydon Mead. The planning authorities are East Hertfordshire District Council and Epping Forest District Council. Hunsdon Mead is registered common land.
Thorley Wash or Thorley Flood Pound is a 17.3-hectare biological Site of Special Scientific Interest in Thorley, south of Bishop's Stortford in Hertfordshire. It was formerly a flood pound for the Stort Navigation, which was decommissioned in 2004 and converted to a more natural state. It was purchased by the Herts and Middlesex Wildlife Trust from the Environment Agency in 2011.
Tewinbury is a 7.5-hectare (19-acre) biological Site of Special Scientific Interest near Tewin in Hertfordshire. The local planning authority is East Hertfordshire District Council, and the site is managed by the Herts and Middlesex Wildlife Trust
Benfleet and Southend Marshes is an 8.1-square-mile (21 km2) Site of Special Scientific Interest (SSSI) in Essex. It consists of mudflats, salt marshes, scrub and wild grassland, and includes the Southend-on-Sea foreshore. It has been so recognised for its biological value, rather than geological. A definition five percent larger forms the Benfleet and Southend Marshes Ramsar site and Special Protection Area. In the centre-west, more than ten percent of the Site is the Leigh National Nature Reserve (NNR), which has been appraised in detail in A Nature Conservation Review as a site of national importance. The SSSI and NNR include the eastern half of Two Tree Island, in Leigh on Sea which is managed by the Essex Wildlife Trust. A narrow majority of the Site is the Southend on Sea Foreshore Local Nature Reserve.
The Crouch and Roach Estuaries are a 1729 hectare biological Site of Special Scientific Interest (SSSI) at the mouth of the Crouch and Roach rivers in Essex. The Crouch part of the SSSI stretches from near Battlesbridge to Foulness Island, and the Roach from Rochford to the junction with the Crouch. Part of the site is in the Mid-Essex Coast Special Protection Area under the EC Directive on the Conservation of Wild Birds, and a Ramsar wetland site of international importance. It is also part of the Essex Estuaries Special Area of Conservation. An area of 65 hectares is managed by the Essex Wildlife Trust as the Lion Creek and Lower Raypits nature reserve and 8 hectares at Woodham Fen, both of which are managed by the Essex Wildlife Trust. A small area is also a geological SSSI, The Cliff, Burnham-on-Crouch.
Foulness SSSI is a 10,702 hectare biological Site of Special Scientific Interest covering the shoreline between Southend-on-Sea and the Crouch estuary in Essex.
